


What Sisters Are For

by LittleMisfitMatch



Series: The Missing A Supports [2]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/F, Family Fluff, Gen, Platonic Relationships, almost angst
Language: English
Status: Completed
Published: 2019-09-10
Updated: 2019-09-10
Packaged: 2020-10-14 05:02:30
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 777
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20595137
Author URL: https://archiveofourown.org/users/LittleMisfitMatch/pseuds/LittleMisfitMatch
Summary: In which Lysithea returns the favor and offers Catherine some sisterly advice.





	What Sisters Are For

**Author's Note:**

> Contains spoilers for Fire Emblem: Three Houses post-time skip.

The high, arched ceilings in the library echoed with the sound of thunder from outside, rain gently pattering across the stained glass windows. Although it was the middle of the day, most of the light that Lysithea had to work with was from the candles, and the short flashes of lightning that illuminated the whole room in a way candles could never. She hoped that five years of being mostly abandoned hadn’t led to any leaks or ruined books, the way the ceiling of the cathedral had collapsed. She wasn’t afraid of lightning the way Caspar had been, but the occasional crash of thunder still had to 

“You know, for all the chandeliers in this place, you’d think they’d have more than candles around all these flammable books.” Lysithea jumped at the voice behind her, which managed to be both rough and soft at the same time. There was something deeply sad behind it, now though. Five years ago you could hear Catherine laughing from across the monastery. Booming and real. She hadn’t laughed much since Rhea’s disappearance.

“Catherine! You shouldn’t sneak up on people like that! It’s not that I’m afraid of ghosts or anything, but if I were, this place could be full of them after the rebellion!” She tried to compose herself, so her ‘big sister’ wouldn’t think less of her, still being afraid of ghosts after all this time.

That, at least, got a smile out of Catherine. She pulled up a chair next to Lysithea and leaned back in it, until Lysithea wasn’t actually sure how it hadn’t tipped over, to stare up at the ceiling. “What are you reading?” she asked, glancing over at the books sprawled out around the table in front of them for a moment, before returning her gaze to the wooden arches above them.

“Nothing important,” Lysithea lied. Truthfully, they were books Linhardt had been looking into, to see if he could help figure out a way to help her with her… condition. She shut the book softly in front of her, and turned her head to look at Catherine, “Is everything alright?”

“Nah, just… needed to gab with a friend for a bit,” Catherine replied, “you know. Melt the stress away. It’s been hard since Rhea…” she trailed off for a moment, not wanting to think about the possibility of Rhea being dead, “Trying to find a purpose. A point in fighting this ridiculous war. Bouncing between sad and angry, and hoping to not end up in the same position that led to me being in the monastery, except that Rhea won’t be here to save me when I’m dying in the mud again.” 

“Life’s too short to dedicate everything you are to just one thing, you know. If I had more time-“ Lysithea stopped herself. Very few knew about her shortened lifespan. She hadn’t even told their professor yet. But this was Catherine. Her sister in Crests. “If I had more time, I would have been able to spend more time enjoying things, instead of having to get everything I need to done before the little I have left is gone.”

Catherine tipped the chair forward to let all four legs rest on the floor again, leaning herself over so she had her elbows back on the table. “She saved my life, and I owe her mine for it. I could have done more to protect her.”

“Listen to yourself!” Lysithea snapped, turning her whole body around to face Catherine fully. Five years had not done much for her patience or temper when it came to people being stubborn. “You’re _Cassandra_, wielder of Thunderbrand! The most powerful Knight of Serios to probably ever live! And here you are acting like a lost child in your own home!” She took a breath. Had that outburst been too harsh? Would Catherine hate her for it?

Instead, Catherine laughed. A full, deep laugh that seemed to make up for all the times she hadn’t over the last few years. “That’s my little sister for you,” she beamed, getting up from her chair, “I appreciate the pep talk, Lysithea.” She patted Lysethia on the head, which truthfully, Lysethia didn’t know how to react to. Or even feel about, for that matter. Then, Cassandra sauntered towards the door, spinning about halfway, to walk backwards for a moment. “And I’m Thunderstrike Cassandra. You’ve earned the right to call me that.” She smiled, and turned herself back around.

“What was that all about?” Lysithea pondered out loud, before shrugging and turning back to her book. The rain had stopped, and the sun was finally starting to peek through the stained glass windows.


End file.
